Unjust enrichment does not bar excise refund where the claimant proved it bore the duty and passed on nothing.

Excise duty paid on exempted pipes used for supplying water fit for human consumption was refundable because the exemption conditions were satisfied by the certificates produced. The documentary record, including invoices, ledger entries, chartered accountant certification and affidavit, showed that the appellants, not the municipal corporation, bore the duty burden, so the bar of unjust enrichment did not apply. The contractual allocation of duty to the contractor supported that conclusion, and the manufacturer's failure to claim the exemption did not defeat the refund claim of the person who actually paid the duty.

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Issues: Whether the appellants were entitled to refund of excise duty paid on exempted pipes, and whether the refund was barred by unjust enrichment when the manufacturer had not claimed the exemption.

Analysis: The pipes were covered by the exemption notification for goods used in supplying water fit for human consumption, and the conditions of the notification were shown to have been satisfied by the certificates produced. The agreement placed the duty burden on the contractor, and the documentary record, including invoices, ledger entries, chartered accountant certification and affidavit, showed that the appellants had borne the duty and had not passed it on to the Ahmedabad Municipal Corporation. In these circumstances, the assumption that the duty burden had been transferred to the municipal corporation was not sustainable. The fact that the manufacturer did not claim the exemption did not defeat the refund claim of the person who actually bore the duty.

Conclusion: The refund claim was not hit by unjust enrichment, and the appellants were entitled to refund.

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